Safety Clearances - Siemens 3VA1 100 A Manual

Description
2.5 Standards and guidelines
2.5.6

Safety clearances

During a short-circuit interruption, high temperatures, ionized gases and high pressures
occur in and above the arcing chambers of the molded case circuit breaker.
Safety clearances are required to:
● allow pressure distribution
● prevent fire or damage caused by any diffused ionized gases
● prevent a flashover to grounded parts
● prevent arcing or short-circuit currents to live sections.
The following safety clearances apply to 3VA molded case circuit breakers:
①
②
A
B
C
D
E
64
Molded case circuit breaker without accessories or with short terminal cover
Molded case circuit breaker with accessories, e.g. phase barrier or long terminal cover
Minimum clearance between molded case circuit breaker and current paths (uninsulated and
grounded metal), see tables below
Minimum clearance between molded case circuit breaker and side walls left / right (uninsulated
and grounded metal), see tables below
Minimum clearance between two horizontally installed molded case circuit breakers, see tables
below;
applicable to fixed-mounted and plug-in versions (see chapter Plug-in and draw-out technology
(Page 201))
Minimum clearance between molded case circuit breaker and control cabinet door
Minimum clearance between live parts of connection system and grounded mounting plate
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02